I have a 2012 GM 2500HD Dmax and pull a 12K GVWR 5er toyhauler with a 2Klb dry pin weight. Have been towing for the last year without any kind of assist and the setup does fine however I am slightly nose high on my TV since I raised the front torsion bars about 1.25" to clear larger tires and remove some of the factory rake. When I hookup my 5er I get ~2.5" of drop putting me about 0.5-0.75" nose high.
I put these on about 2 weeks ago and have been driving around empty trying to see if they affect ride. Any affect would be a deal breaker for me since its my daily driver. Crossing railroad tracks and some bad roads (I live in CA) I have yet to feel any impact of using these when running empty. Last week I pulled the 5er about 20mi and there is a slight but noticeable improvement. When I hooked up I'm now getting about 2.0" of drop compared to previous 2.5".
Overall I like them and since they don't affect unloaded ride there is nothing to lose by running them. No drilling required as the stock overload leaf already has a hole for the rubber bushing that comes from the factory. All I had to do was put a floor jack under the hitch receiver and unload the leafs to make room to slip these in. Should also work on earlier year GM truck but not sure about Ram/Ford. They are made by Energy Suspenstion (Part# 99102)and are 11/16" tall.
2015 Attitude 28SAG w/slide
2012 GMC 2500HD SLT Duramax
B&W Turnover w/Andersen Ultimate 5er hitch